In order to control process sequences, automation systems, for example, field bus systems, are used in which, as a rule, a programmable logic controller (PLC) is connected to sensors and actuators by way of a bus in order to observe and control the process. Process control is performed, for example, by a cycle-oriented control program that, as a rule, is permanently stored by the manufacturer in a PLC unit as an operating system. The cyclically operating control program first detects the status of all of the sensors that are connected to the PLC unit and uses the data it acquires to produce a process diagram of all inputs to the PLC unit. Then the cycle-oriented control program cedes control to a user program. The user program now uses the process diagram of all inputs to generate a process diagram of all outputs, i.e., the output signals designated for the attached actuators. Then the user program cedes control of the system back to the operating system, i.e., the cycle-oriented control program. The control program ensures that the output signals are transmitted to the respective actuators. Then the control cycle begins again from the beginning.